1. Technical Field
The present disclosure relates to LED (light emitting diode) illumination systems, and more particularly to an LED illumination system having a low energy consumption.
2. Description of Related Art
LEDs have been available since the early 1960s. Compared with the conventional light sources, such as fluorescent lamp, halogen lamp and incandescent lamp, the LEDs have a higher electro-optical conversion efficiency. Thus, nowadays LED usage has been increased in popularity in various applications, particularly, the applications needing large power consumption, in order to reduce operation cost of these applications.
Road lamp is one type of lamps consuming a larger amount of power; thus, it is extremely desirable to replace the conventional road lamps with the LED road lamps. However, the LED road lamp always keeps a constant brightness all over the illumination period thereof, even in the late night. In fact, at the late night, a traffic flow is low, and thus there is no need to provide such a high intensity as that at early night. The LED lamp would still waste a large amount of power to maintain the constant brightness during its whole operation period.
It is thus desirable to provide an LED illumination system which can overcome the described limitations.